Diodes Incorporated PI5C3244LE

Overview

PI5C3244LE from Pericom Semiconductor is an 8-bit, dual-port bus switch IC with two independent 4-bit switch banks (1A/1B and 2A/2B), pinout- and function-compatible with 74FCT244T, 74F244, and 74ALS/AS/LS244 logic drivers. It features near-zero propagation delay (0.25 ns), 5 Ω typical on-resistance, ultra-low quiescent current (0.2 µA), and operates at 5 V ±5% over –40°C to +85°C for notebook and low-power embedded bus isolation.

For engineers reviewing the PI5C3244LE datasheet, PI5C3244LE pinout, PI5C3244LE application, or PI5C3244LE equivalent, key selection criteria include its bidirectional 5 Ω switch resistance, dual active-low enable control (BE1/BE2), TTL-compatible input thresholds (VIH = 2.0 V, VIL = 0.8 V), and Pb-free TSSOP-20 packaging for space-constrained PCB layouts.

Technical Context

The PI5C3244LE implements eight independent analog bus switches-four per port-controlled by separate active-low enables (BE1, BE2). Each switch provides a direct, low-impedance metal path between A and B terminals when enabled, with no added logic delay beyond RC time constant (RON × CL).

It uses CMOS transmission-gate architecture with rail-to-rail analog signal handling (–0.5 V to +7.0 V), supports hot-swap operation via high-impedance off-state (IOZH ≤ ±1 µA), and maintains signal integrity with low capacitance (CON = 12 pF, COFF = 6 pF) and negligible ground bounce.

Key Specifications

Pinout & Package

PI5C3244LE is housed in a 20-pin Pb-free Green TSSOP (Thin Shrink Small Outline Package), 173-mil wide, with 0.65 mm pitch and exposed thermal pad (not electrically connected). Pin 1 marked by dot; pin 10 and 11 are GND and VCC respectively.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit bus switch applications.

Compared with SN74CBT3244CPWR and PI5C3257LEX, PI5C3244LE delivers superior power efficiency (0.2 µA vs. 5 µA/0.2 µA) and granular dual-port control-critical for dynamic bus partitioning in portable and modular systems.

Availability

PI5C3244LE is available at Aetrix Electronics and suitable for notebook memory management, industrial PLC I/O expansion, and USB 2.0 docking station design requiring stable component supply and RoHS-compliant packaging.

Supply support for PI5C3244LE includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Pericom Semiconductor was a fabless provider specializing in high-speed interface, timing, and signal-integrity solutions before its acquisition by Diodes Incorporated in 2016; its legacy portfolio remains widely deployed in industrial and computing infrastructure.

The PI5C3244LE belongs to Pericom's PI5C bus switch family, engineered specifically for low-latency, low-power bidirectional signal routing in space-constrained 5 V logic systems-emphasizing analog-switch fidelity over digital logic functionality.

FAQ

Is PI5C3244LE compatible with 3.3 V logic systems?

No. PI5C3244LE is specified only for 5 V ±5% operation (4.75–5.25 V). Its VIH minimum is 2.0 V and VIL maximum is 0.8 V, but internal switch threshold and RON performance are optimized for 5 V rail. Using it with 3.3 V supplies risks incomplete turn-on and elevated on-resistance beyond 15 Ω.

Can BE1 and BE2 be tied together for single-enable operation?

Yes. BE1 and BE2 may be connected to a common enable signal without adverse effect. The truth table confirms identical behavior when both are asserted low, and the device draws only 0.2 µA quiescent current regardless of enable state-making shared control electrically safe and power-neutral.

Does PI5C3244LE support hot-swap insertion into a live 5 V bus?

Yes. With IOZH ≤ ±1 µA and no internal latching, the PI5C3244LE enters high-impedance state immediately upon power-up or enable deassertion. Its absolute maximum ratings allow –0.5 V to +7.0 V on all I/O pins, enabling safe insertion into powered-backplane environments without sequencing constraints.

What is the maximum capacitive load supported per switch channel?

The datasheet specifies tPLH/tPHL test conditions at CL = 50 pF. While not explicitly rated beyond that, the 0.25 ns delay corresponds to an RC time constant of ~12.5 Ω·pF; with 5 Ω RON, this implies practical stability up to ~100 pF. For loads >50 pF, verify signal rise/fall times and overshoot in prototype validation.